STRUCTURE MAKES FUNCTION

Phospholipid bilayer

Energy source (butter)

Important Energy source (oils)

Steroids

Cholesterol

Testosterone (hormones)

Carbohydrates

Monosaccharide

Fructose

Glucose

Disaccharide

Lactose

Sucrose

Polysaccharide

Storage

Starch

Glycogen

Structural

Cellulose

Starch

Hormones

Regulation

Level

transcription

RNA Processing

Transport to cytoplasm

Translation

Protein Processing

Expression

Metabolism

Free Energy

Equilibrium

ΔG = 0 , Equilibrium

Max stability = Equilibrium

Free energy decreases closer to equilibrium & Vice Versa.

System never moves away from Equilibrium Spontaneously

Equilibrium= Dead System

ΔG

Universe = System + Surroundings

When temp. and pressure are uniform

ΔG = ΔH -TΔS

ΔG> 0, non-spontaneous, endergonic

ΔG< 0 , spontaneous, exergonic

ΔG = ΔG final - ΔG initial

Images

Energy Transformation

Metabolic Pathways

Catabolic Pathway

Anabolic Pathway

Energy

Kinetic Energy

Thermal Energy

Heat: transfer of thermal energy

Chemical Energy

Thermodynamics

Surrounding vs. system

1st Law: Principle of Conservation of Energy

2nd Law: Energy transfer increases entropy of Universe

Entropy and Enthalpy

Large amount of energy transferred is lost as heat

Coupling

Work

Chemical Work

Transport Work

Mechanical Work

Phosphorylation

Phosphorylated intermediate: key to coupling

Coupling occurs by endergonic and exergonic reactions fueling each other.

Enzymes

Activation Energy

Energy required to get to the "top of the hill"

Transition state

Has enough energy to break bonds

How they work

Catalyst

They lower Ea

Enzyme -substrate complex

Converts substrate to products

Induced fit via malleable equilibrium

Optimal conditions

pH

Temperature

Cofactors

Non protein helpers

Competitive inhibitors

Bind to active site

Non competitive inhibitors

Bind somewhere other than active site

Enzyme Regulation

Allosteric Regulation

Not bound on active site

Oscillating subunits

Activators

stabilize subunits

Inhibitors

stabilize subunits

Enzymes and substrates are compartmentalized
within the cell

Cooperativity

allosteric activation

substrate binds to active sites

amplifies enzyme response

affects other binding sites

Cellular Respiration

Catabolic Pathway, redox

OIL (Reducing agent)

RIG (oxidizing agent)

NAD+ oxidized state

NADH reduced state

Substrate-level phosphorylation

Phosphate for ADP comes from substrate
rather that an inorganic phosphate

Substrate-level phosphorylation

Powered by redox reactions

Glycolysis

Energy Investment Phase

Glycolysis occurs whether or not O2 is present

Step 1

Hexokinase transfers phosphate from ATP to Glucose

Step 3

Phosphofructokinase transfers a phosphate from ATP to opposite end of the sugar (this is the second ATP)

Step 5

Two three carbon sugars are left
(Glyceraldehyde 3-phosphate and
Dihydroxyacetone Phosphate)

G3P and DHAP which convert between each other

Energy Payoff Phase

4 ATP formed, 2 NADH, 2 H+, 2 pyruvate, 2 H2O

Net

Glucose --> 2 Pyruvate + 2 H2O
2 ATP, 2 NADH, + 2 H+

Occurs in the cytosol

Pyruvate oxidation

Occurs in the mitochondrial matrix

Step 1

Pyruvate dehydrogenase complex removes the CO2 from the pyruvate.

Methionine first amino
acid placed in protein

Step 2

Remaining fragment is oxidized forming acetate and releasing electrons forming NADH.

Step 3

Acetyl CoA is formed via coenzyme A

Citric acid cycle

Two reduced carbons enter the cycle with Acetyl CoA, and two oxidized carbons leave in the form of CO2

Step 1

Acetyl CoA becomes citrate

Step 3

Isocitrate is oxidized, reducing NAD+ to NADH and losing a CO2 molecule. Isocitrate becomes a-ketoglutarate

Step 4

Another CO2 is lost, NAD+ becomes NADH. a-ketoglutrate becomes Succinyl CoA

Total yield

One glucose--> 6 NADH, 2FADH2, 2 ATP

Oxidative phosphorylation

Electron Transport Chain

When a complex receives en electron, it is reduced, then oxidized when it is passed onto the next complex

The electrons travel from complex I and II to complex Q, then to Complex 3 followed by complex 4.

Total: 2 e-, 2H+, 1/2 O2

Occurs in the inner mitochondrial membrane

Electron carriers

NAD+

FADH2

Cytochromes

Chemiosmosis

ATP Synthase

makes ATP from ADP and inorganic phosphate

H+ concentration gradient on the outside of the inner membrane couples the redox reactions of the ETC

26 or 28 ATP produced

Anaerobic respiration

Fermentation

Alcohol fermentation

Pyruvate is converted to ethanol

Lactic acid fermentation

pyruvate is reduced by NADH to form lactate

Photosynthesis

Photosynthesis makes food

autotrophic

Makes its own food

Choloroplasts

Thylakoid

Where light reactions occur

split water

release O2

Produce ATP and form NADHP

grana

Stroma

Calvin cycle

CO2--> sugar

Uses ATP for energy

Uses NADPH for reducing power

6CO2 + 12H2O + Light Energy --> C6H12O6 + 6O2 + 6H2O

Photosynthesis is a redox

H2O is oxidized

CO2 is reduced

Light reactions

Wavelengths

Visible light wavelengths drive photosynthesis

Photon

Pigment absorbs

Photosytems

PS I

P700 molecules

PS II

P680 molecules

Both contain a reaction-center complex and a light harvesting complex

Electron flow

Linear

Uses both PS's and produces, NADPH, ATP, AND O2

Cyclic

only one PS is used, produces only ATP

Calvin Cycle

Uses ATP and NADPH to reduce CO2 and sugar

One molecule of G3P exits per three CO2

Alt. mechanisms for Carbon Fixation

Photorespiration

O2 subs for CO2 in rubisco sites

C3 plants

Close stomata conserving water

C4 plants

Incorporate CO2 in mesophyll cells

then exported to bundle-sheath cells

CAM plants

open their stomata at night

Positive

Activator

Increased RNA transcription

Negative

Repressor

Basal level

Beta Galactosidase

Permease

Beta Galactosidase acetylase

CAMP levels high

Normal

Shrivel

Lyse

Flaccid

Turgid

Ideal conditions

Plasmolyzed

Cytoplasm

NUcleus

Inactive enzyme

GTP displaces GDP

active enzyme